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Power Tools 1993 November - Disc 2
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Power Tools Plus (Disc 2 of 2)(November 1993)(HP).iso
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dbavail.txt
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1993-06-04
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EDITORIAL CONTACT: PRCS4700329
Lynne Hanson
(408) 447-1415
HP INTRODUCES REPLICATION FOR ITS MAINFRAME-CLASS
RDBMS TO ENABLE DATABASE SHADOWING
PALO ALTO, Calif., May 5, 1993 -- Hewlett-Packard Company
today announced a new replication capability for its HP
ALLBASE/SQL relational-database-management system (RDBMS).
The add-on product, called HP ALLBASE/Replicate, allows all
or part of an HP ALLBASE/SQL database to be "shadowed"
(replicated) to other locations on the same or different
systems over a network.
The ability to replicate and synchronize data --
potentially over vast geographical areas -- means users can
increase fault resilience (protection) by maintaining shadow
copies of the database. It also provides them with local
access to remote data and improved database performance
through offloading read-only applications to the shadow
database.
HP's RDBMS' shadowing implementation offers real-time
updates and updates on systems not operating continuously.
These two features let users back up their shadow databases
while still using the primary one. This capability promotes
24-hour system availability, instant remote-system updates
and built-in disaster recovery in case of system failure.
"Replication is being seen increasingly as a database-
updating mechanism that improves the accessibility and
reliability of distributed data in a network environment,"
said Cathy D. FitzGerald, HP's software/networks marketing
manager for HP's Commercial Systems Division. "HP
ALLBASE/Replicate is HP's response to customers' requests
for this kind of database enhancement and makes HP one of
the first major SQL database providers to offer this
capability."
Meeting Customer Requirements
Previously, most distributed database transactions have
been performed on an all-or-nothing basis through a
two-phase commit protocol that requires the sender and
receiver to be active. Since networks are not always up and
running (especially over a vast geographical area),
two-phase commit is not always practical or cost-effective.
As a result, HP ALLBASE/Replicate offers an alternative
that simplifies updating database transactions, increases
database redundancy and improves control over the network
traffic load.
By maintaining shadow copies on the network, HP
ALLBASE/Replicate automates updating and synchronizing
distributed database transactions according to predetermined
customizable options. In this way, if the primary copy of
an HP ALLBASE/SQL database environment is unavailable,
application processes could continue to operate by switching
to one of the shadow database copies.
HP ALLBASE/Replicate also improves access to remote
databases. In the distributed environment, often it is
necessary to access a database at a different site. Since
establishing a remote login capability for each location is
expensive and/or impractical, HP ALLBASE/Replicate provides
the capability to view pieces of regional data as a whole by
combining them at one site.
As distributed databases include more data, there are
cases in which remote sites must operate non-stop and
unattended. To ensure that remote data is backed up
reliably, HP ALLBASE/Replicate enables the primary and
secondary database copies to be exact matches. In addition,
since the secondary database does not always need to mirror
the primary database, remote backup operations are more
flexible.
How It Works
HP ALLBASE/Replicate is designed to give users the
flexibility of multiple copies of the same HP ALLBASE/SQL
data at different sites over a network. In this way, HP
ALLBASE/Replicate provides version independence by keeping
multiple secondary copies of the data synchronized with the
master copy that resides elsewhere on the network.
For example, in the event that a system running a
replicate version of the database is not operational, HP
ALLBASE/Replicate follows steps to ensure that it can be
synchronized with the master database once the system starts
functioning again.
To begin synchronization, the secondary database
determines how far behind the master database it has fallen.
Then, the secondary database finds the last transaction it
missed in the master database and makes that transaction the
synchronization point. Finally, the primary database
transmits all the latest records to the secondary database,
which makes the updates.
HP ALLBASE/Replicate Components
HP ALLBASE/Replicate consists of two main components.
One is an engine that changes the HP ALLBASE/SQL environment
to facilitate replication. The second is an application
that runs on top of the engine and executes the resync
process. Users of HP ALLBASE/Replicate have the option of
buying the Replicate application from a third party or
customizing the HP-supplied version.
Specifically, HP ALLBASE/Replicate has added extensions
to the HP ALLBASE/SQL interface that allow it to support
replication-driven changes to the HP ALLBASE/SQL log
manager. HP ALLBASE/Replicate also includes a set of
intrinsic specifications that allow the resync application
to access these changes.
The customizable component of the overall solution, the
resync application, dictates the primary and secondary
synchronization points used by the various replication
processes in updating the database.
HP ALLBASE/Replicate runs across the HP 9000 workstation
and business servers, and HP 3000 business system families
and supports database shadowing between the two
environments.
About HP ALLBASE/SQL
As part of its broader information-management strategy,
HP offers HP ALLBASE/SQL to users interested in reducing
data-center costs while moving to open systems and
client/server computing.
"Designed to service mainframe-class workloads in a
data-center environment, HP ALLBASE/SQL typically costs
one-tenth the price of traditional mainframe RDBMSs, yet
offers customers better performance and functionality," said
FitzGerald.
HP's ALLBASE/SQL supports high-volume, online,
transaction-processing computing and coexists with HP and
non-HP databases. HP ALLBASE/SQL runs across all HP 3000
business computers and HP 9000 workstations and business
servers.
U.S. Prices and Availability
HP ALLBASE/Replicate is expected to be available in June.
Prices are expected to range from $6,800 to $19,900 on the
HP 9000 Series 800 business servers and from $2,400 to
$23,400 on the HP 3000 900 Series business computers.
Prices for a version that will run on the HP Apollo 9000
Series 700 workstations are being determined.
Prices for HP's ALLBASE/SQL database range from $2,250 on
a small, departmental server to $70,350 for a version
supporting thousands of users on the HP Corporate Business
Systems.
Hewlett-Packard Company is an international manufacturer
of measurement and computation products and systems
recognized for excellence in quality and support. The
company's products and services are used in industry,
business, engineering, science, medicine and education in
approximately 110 countries. HP has 93,100 employees and
had revenue of $16.4 billion in its 1992 fiscal year.
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